Portable dictation apparatus



July'14, 1959 F. w. ROBERTS EIAL PORTABLE DICTATION APPARATUS 3 Sheets-Sheet 1 Filed April 30, 1956 INVENTORS FREDERICK w. ROBERTS JOHN R. MONTGOMERY @XW ATTORNEYS July 14, 1959 F. W. ROBERTS ETAL PORTABLE DICTATION APPARATUS Filed April 30, 1956 ,5 Sheets-Sheet 2 l /32 I341: I26 20 I29 .INVENTORS FREDERICK W. ROBERTS JOHN R. MONTGOMERY July 14, 1959 w; ROBERTS ETAL 2, 4,

PORTABLE orcm'rxon APPARATUS Filed April so. 1956 I 3 Sheets-Sheet 3 INVENTORS FREDERICK wfloesnrs IOHN R; MONTGOMERY ATTORNEYS tates PORTABLE DIcTArroN APPARATUS Application April 30, 1956, Serial No. 581,601 14 Claims. (Cl. 24255.13)

This invention relates to recording machines. More particularly, this invention concerns recording machines sufficiently small in size and light in weight to be carried easily in one hand, and which include a self-contained source of power for portable operation. Such machines are especially suited for use while travelling, but also find application in a variety of other situations where conventional recording machines are inappropriate.

Although a number of miniature recording machine constructions have been proposed heretofore, all of these have had certain disadvantages which limited their useful ness commercially. An eilective machine of this general type must meet certain requirements, and yet be compact, light-weight and relatively inexpensive to manufacture. For example, provision must be made for rapid and easy replacement of recorded media with fresh media, and the machine should be designed for substantial recording time between such replacements. Also, the recording media should be in a form such that replacement media may readily be carried, e.g. along with the recording machine, without being subjected to damage from ordinary abuse typically encountered during travel. Appropriate controls must, of course, be provided for turning the machine off and on, as well as for playing back portions of previously recorded material, and such controls should be arranged for convenient access and simple operation.

Accordingly, it is an object of the present invention to provide a small-sized recording machine especially adapted for portable operation that is superior to such machines provided heretofore. It is a further object of this invention to provide such a machine that meets the general requirements outlined above, and yet is sufliciently light and compact that it may readily be carried, e.g. in the pocket of a coat. Other objects, advantages, and aspects of this invention will be in part apparent from, and in part pointed out in, the following description of a preferred embodiment thereof considered together with the accompanying drawings, in which:

Figure 1 is a perspective view of a recording machine constructed in accordance with the present invention, particularly showing the outer casing and operating controls;

Figure 2 is a plan view of the machine of Figure 1 with the cover removed;

Figure 3 is a plan view of the interior of the cover;

Figure 4 is a perspective view of the tape magazine, shown standing in upright position;

Figure 5 is a vertical section of the tape magazine taken along line 5-5 of Figure 4;

Figure 6 is a horizontal section of the tape magazine taken along line 66 of Figure 5, and also showing the drive hubs which cooperate therewith;

Figure 7 is a detail section view, taken along line 77 of Figure 5, showing the central portion of one of the magazine tape reels held in place on the corresponding drive hub;

Figure 8 is a plan view of the recording machine of 2,894,?fi9 Patented July 14, 1959 Figure l with the tape machine and protective guide shield removed; and

Figure 9 is a sectional view of the recording machine of Figure 8, particularly showing the drive and control linkage mechanisms located beneath the main support plate.

Referring now to Figure 1, the operating elements of the recording machine (to be described hereinbelow in more detail) are contained within an attractive rectangular casing 10 having a length of about 6%", a width of about 4 /2, and a depth of about 2,". The particular machine described herein is of the type which makes a magnetic sound record on a flat ribbon-like tape of magnetizable material, i.e. it utilizes one form of linear recording medium (the term linear is used here to designate long, thin media as distinguished from area media such as a disc). It is desired to point out, however, that the present invention in its broader aspect is applicable to all types of recording machines using any form of linear recording medium, e.g. wire-like material, etc.

Extending out through the upper side of the case 16 are the operating controls, including an on-oif lever 12, a tape movement control lever 14, a recording volume control 16, and a reproducing volume control 18. The tape movement control lever has three positions: record, reproduce, and rewind. A microphone 20 (serving also as a sound receiver when the machine is conditioned for play-back operation) is connected to the machine through a cable 22 having a plug 24 at its other end which is engageable with a corresponding socket in the machine. A removable cover 26 forms one side of the casing 10, and is releasable from the casing by means of a catch lever 28.

Before proceeding with a detailed description of the internal structure of the machine, a brief review of its operation will first be presented: Within the casing 10, conventional means are provided for amplifying the electrical signals developed by the microphone 20 and for recording on the magnetizable tape in accordance with these amplified signals. When the control lever 14 is in record position and the on-olf lever is moved to on, the tape is driven past the magnetic recording head by a governor-controlled electric motor powered by two small batteries in the casing; another small battery supplies power for the sound amplifier. When the control lever is moved to rewind position, the motor drives the tape in reverse direction at a relatively high speed, and the amplifier circuitry is switched so that no magnetic impressions are placed on the tape. Shifting the control lever to reproduce position causes the tape to be driven at normal speed in a forward direction (as in record), and the amplifier circuitry is conditioned to deliver amplified electrical signals to the microphone (serving as a receiver) in accordance with the magnetic impressions sensed by the recording head serving as a reproducing head. The volume controls 16 and 18 operate to vary resistances in the amplifier circuitry so as to set the desired volume when in record and reproduce conditions.

Referring now to Figure 2, which is a view looking down into the recording machine with the cover 26 removed, the magnetic tape is contained within a thin, generally rectangular magazine 30 extending substantially the full length of the casing 10 and which may be lifted up out of the casing in a simple manner manually, e.g. by gripping the inset waist portion 32 between the thumb and forefinger. The tape is carried within the magazine on two reels, the centers 34 and 36 of which protrude through corresponding apertures in the flat faces of the magazine. These apertures include slots 38 and 40 to permit a view of the amount of tape on each reel,

e) and these slots in turn are aligned with small windows 42 and 4-4 (Figure 1) formed in the cover 26 so that the user may readily estimate the amount of recording time remaining.

The tape 46 moves horizontally (referring to Figure 2) along the upper edge of the magazine 30 in travelling from one reel to the other, and passes by various mag.- netic recording elements and drive mechanisms located beneath a protective guide shield 43 which is secured to the machine by means of a screw 59. This shield is formed along its lower edge with two curved extensions 52 and 54 which serve to assure that the tape 46 is guided into its proper position relative to the recording and drive elements when the magazine is inserted into the casing. The magazine is anchored in position with respect to movement parallel to its flat faces by two conical studs 56 and 58 which extend upwardly from be neath the magazine through corresponding holes in the lower corners of the magazine; one of these holes is circular to precisely position the magazine, and the other is oval-shaped in order to avoid frictional binding due to adverse build-up of manufacturing tolerances.

The cover 26 shown in Figure 3 includes along its lower edge a raised lip 66 which is insertable within a corresponding slot 62 (Figure 2) formed in the upper side of the machine case 10. The other edge of the cover is held in place by a catch generally indicated at 64 which includes a fixed pawl 66 engageable with an aperture formed in a spring strip 68 on the machine. The catch lever 28 (Figure 1) is rotatably mounted upon an elongated pin 70 (Figure 3) secured to the cover 26 and carries with it a forked member 72 which, when the catch lever is moved outwardly away from the cover, presses against the spring strip 68 to release it from the pawl 66 and thereby permit the cover to be removed from the casing 10.

In the central portion of the cover 26 there is secured a rectangular spring plate 74- having a flattened end '76 which presses against the central region of the magazine 30 when the cover is properly in place, to hold the magazine securely in position. On each side of this spring plate there is secured to the cover a spring arm '78 and on the ends of these arms are mounted circular nylon pads 80 which engage the centers 34 and 36 of the tape reels in a manner to be explained below.

As shown in Figure 4, the magazine 30 comprises two mated shells 30a and 30b which are secured together by five screws 82. These shells comprise identical castings so that the magazine is symmetrical front-to-back. The magnetic recording elements in the machine are so arranged that only half of the width of the tape 46 is recorded on at a time. By virtue of the symmetry of the magazine, after the full length of the tape has been recorded upon (but only half-width), the magazine may be removed and then replaced upside-down in the case to record on the other half of the tape.

Turning now to Figure 5, the interior arrangement of the magazine 36 is there shown in detail. Within the magazine is a supply reel 84 and a take-up reel 86. During recording, the tape is pulled at a substantially constant lineal velocity from the supply reel, and the take-up reel is rotated (through a slipping-clutch arrangement shown in Figure 9) at a speed sufficiently great to prevent the build-up of any slack in the tape. In its passage from the supply reel to the take-up reel, the tape passes over a series of fixed guide pins 38, fit), 92, 94, 96 and 98 having smooth exteriors; these pins are permanently secured to one of the mated shells 30a or 313]). In the regions where the tape passes over the central pins 92 and 94, a pair of transverse arms 100 and 102 (see also Figure 4) are provided to hold the tape in proper position for insertion of the magazine into the casing.

To assure that the tape is held firmly in place when the magazine is outside of the case, an automatic brake structure is provided. This includes (referring now to the upper left-hand corner of Figure 5) a leaf-spring arm 104 secured at its lower end to the magazine and provided at its upper end with a felt pad 106 urged against the portion of the tape 4-6 passing over the guide pin 38. At the right-hand corner of the magazine there is a similar leaf-spring arm 1% with a felt pad 110 urged against the portion of the tape passing over the guide pin 98.

Referring now to Figure 2, when the magazine is inserted into the casing, a small fixed pin 112 secured to tie recording machine proper, extends through an oval slot 114 (see also Figures 4 and 5) in the upper right hand corner of the magazine and engages the spring arm 168 to move it to the right and thereby lift its felt pad 110 out of engagement with the tape 46. This action reduces the driving force required to pull the tape onto the take-up reel 86 during recording. As shown in Figure 4, the spring arm 168 is formed with small ears 1680 which protrude laterally out through the oval slot 114 at a slight angle with respect to the axis of the pin 112 to insure positive engagement with this pin, the tip of which is pointed.

In the upper left-hand corner of the magazine, a similar small pin 116 extends through an oval slot 118, but when the machine is conditioned for recording this pin is out of engagement with the tipped ears 104a of the corresponding spring arm 164 This pin 116, however, is secured to an element of the control linkage mechanism (to he described) which is so arranged that when the control lever 1 is shifted to its rewind position, the pin moves in a left-hand direction to engage the spring arm 164 and lift its felt pad 106 out of engage ment with the tape 46 passing over the guide pin 88. This reduces the driving force required when the tape is being rewound at relatively high speed onto the supply reel 84.

Referring now to Figure 6, it can be seen that each of the reel centers 34 and 36 includes a ring portion 126 and 122, respectively, having an axial length greater than the interior width of the magazine 3t). These rings therefore protrude through the corresponding magazine apertures and the ends thereof are approximately flush with the outer side surfaces of the magazine. The protruding portions serve as flanges to prevent excessixe lateral movement of the reels 84 and 86 when the magazine is outside of the casing 10.

Each of these ring portions 120 and 122 includes a central wall 124 and 126 extending transversely across the interior thereof to form a pair of opposed, cylindrical recesses opening towards the outside of the magazine 30. The sides of each recess are formed with a rotary coupling structure comprising a set of spline-like gear teeth engageable by corresponding sets of teeth on a pair of drive hubs 123 and extending through the main support plate 132 in the recording machine proper.

The individual teeth in each set are spaced a substantial distance apart peripherally, i.e. in the nature of a conventional gear with every other tooth missing, to lessen the probability of interference when the magazine is inserted in the casing. Also, the hubs are formed with tapered ends 128a and 130a which insure positive engagement with the loosely-held rings 12%) and 122 when the magazine is placed in the machine, and are rotatably driven by hub shafts 129 and 131 in accordance with the setting of the machine control levers 12 and 14. The hubs serve not only to supply rotary driving force to the reels, but also to provide bearing surfaces for aligning the reels accurately with respect to the other recording machine elements.

These features are more clearly shown in Figure 7 wherein one hub 128 is engaged with the internal teeth of the lower recess of the ring portion 120. The transverse dividing wall 124 is formed on opposite sides thereof with upstanding pins 134a and 1341; disposed vertically with respect to the plane of the wall. (Similar pins 136a and 1361; are formed on the dividing wall 126 of the other ring 122.) The pin 134b facing the hub 128 engaged with the supply reel 84 extends into a corresponding vertical bore formed in that hub Without contacting the bottom of the bore. The tip of the opposing pin 134a is engaged by the nylon pad 80 which is urged against this tip by the spring arm 78 (associated with the cover 26) and serves as a thrust bearing for the rotation of the supply reel.

To further assure quick engagement between the splinelike teeth on the hubs 128, 130 and the corresponding sets of internal teeth on the reel centers 34, 36, these teeth all are tapered radially so as to present relatively narrow edges at the tips thereof. Figures 4 and 5 best show this tapering of the internal teeth on the reel centers, while Figure 8 shows this tapering of the teeth on the hubs. In addition, referring now particularly to Figure 6, the outer ends of the teeth on the reel centers 34, 36 are cut back at an angle (eg of about 45) to form, in effect, tapered surfaces which face, and are engageable with, the ends of the hubs when the magazine is being secured in place on the recording machine. This cut-back of the ends of the teeth serves, like the tapered ends 128a, 130a of the hubs, to produce a lateral force on the reels while the magazine is being installed, and

thereby aids in assuring that these reels are automatically aligned to obtain quick and easy engagement between the reels and the hubs.

It will be apparent that such a magazine construction is advantageous particularly in that no precision machining or other expensive techniques are necessary in its manufacture. For example, the spacing between the rings 120 and 122 and the edges of the corresponding magazine is not a critical dimension because the hearing surfaces for rotation of the reels are in the recording machine proper. Also, this spacing may be relatively wide (as shown) since the hub construction assures proper engagement with the reels even though they are held in only approximate alignment when the magazine is outside of the casing. Thus, the magazine parts may be produced and assembled without applying severe manufacturing tolerances to the dimensions or surface finish thereof. Because each recording machine will normally require a number of tape magazines, this simplification of design is especially important in that the construction costs per magazine unit will be relatively low.

Figures 8 and 9 show details of the mechanism for controlling the machine operation and driving the magnetic tape. Figure 8 represents a plan View showing the main support plate 132 on which the hubs 128 and 130 are mounted, while Figure 9 represents a sectional view of the structure immediately beneath, and secured to, this support plate. In both of these views, the on-off lever 12 is in its 0 position and the control lever 14 is in its reproduce position.

Referring now to the upper right-hand corner of Figure 9, an electrically-operated motor 140 is provided for driving the tape and the reels in the removable magazine 30 (described above). This motor is powered by small batteries (not shown) contained in the casing 10, and its speed is maintained substantially constant by a governer within the motor housing. The output shaft 142 of this motor is provided with a worm-gear drive assembly, generally indicated at 144, which transmits motion through a resilient endless band 146 to a central drive shaft 148. This shaft carries with it a flywheel (not shown, in order to simplify the presentation) and a capstan 158 extending vertically upwards through the support plate 132. The capstan is partially enclosed within a U-shaped protective housing 152 (Figure 8) having a bearing insert 154 for rotatably supporting the upper end of the capstan.

Immediately above the capstan 150 is a pressure roller 156 formed of resilient material and arranged, when the machine is turned on and conditioned for recor or reproduce, to move down and press the magnetic tape against the capstan. This roller is rotatably mounted on pivot pin 162 is produced by operation of either of the,

control levers 12 or 14 in a manner to be explained.

The lower edge of the right-hand end of the control arm carries two upstanding pins 164, and the tape drops down between these pins and the roller 156 when themagazine 30 is inserted into the casing 10. When the roller moves down to engage the capstan, these pins move by the capstan on either side thereof so as not to interfere with driving of the tape. Before removing the magazine, the roller is shifted up out of engagement with the capstan, and the two pins 164 carry the tape away from the capstan so that there will be no interference with the capstan housing 154 when the tape is lifted out with the magazine.

The on-olf lever -12 includes a ring base 166 loosely pivoted about a shaft 168. Pivotally pinned to the periphery of this base is a small yoke 170 the remote end of which is formed with forked arms surrounding a pin 172 secured to the left-hand end of the control arm 160. This yoke is so arranged that, when the lever 12 is in its foff position (as shown), it holds the end of the control arm depressed, against the tension of a spring 174, with the pressure roller 156 out of engagement with the capstan 158. When the lever 12 is moved up (i.e. to its on position), the resulting clockwise rotation of the base 166 carries the small yoke 170 upwards and permits the control arm to move under spring tension until the roller and capstan are firmly engaged. This upwards movement of the lever 12 also operates a set of switch contacts, diagrammatically indicated at 175, to connect the batteries to the sound amplifier and to the motor 140, and the capstan therefore starts rotating to drive the magnetic tape at constant lineal speed.

During recording or reproducing, it is necessary also to rotate the take-up reel 86 so as to prevent any slack from building up in the tape driven by the capstan, and this is accomplished as follows: The central drive shaft 148 carries with it a pinion 176 which engages a gear wheel 178 rotatably secured to a rockable transfer arm 180. Mounted on and rotatable with this gear wheel is a smaller friction wheel 182 the outer periphery of which is drivably engaged with the resilient ring 183 surrounding a relatively large disc 184. Rotation of this disc is transmitted to the hub shaft 131 through a slipping-clutch arrangement comprising a plate 184 which is fixed to the shaft and formed with spring fingers 185a pressed against the under surface of the disc. Accordingly, when the machine control lever 12 is moved to its on position to energize the motor 140, the hub shaft rotates the hub 130 (Figure 6) and the take-up reel 86 to eliminate slack in the tape delivered by the capstan 150.

When the machine is conditioned for rewind," it is necessary to apply the motor drive in a reverse direction to the supply reel 84. This is accomplished as follows: The transfer arm 180 is pivotally secured at its lower end to a pin 186 so that it may be rotated counterclockwise to move the gear wheel 178 to the left (while still maintaining driving engagement with the pinion 176) against the tension of a spring 188 fastened to the top of the transfer arm. A very small movement of the transfer arm brings a large friction wheel 190, which is rotatably mounted with the gear wheel 178, into contact with an idler wheel 192 rotatably mounted on the end of a pivot arm 194, and disengages the friction wheel 182 from the disc 184. The idler wheel transmits rotary movement to a small friction disc 196 secured to the hub shaft 129, to drive the hub 128 (Figure 6) and the supply reel 84 in a direction to rewind the magnetic take back onto the supply reel. It may be noted that the gear train in this in- 7 stance is arranged to provide a tape speed during rewind that is considerably higher than during recording or reproducing.

This counterclockwise rotation of the transfer arm i813 results from moving the control lever 14 (Figure 8) upwards to its rewind position, as follows: The control lever is anchored to the vertical shaft 1M8 to which is fixedly secured (Figure 9) a crank arm 201). The remote end of the crank arm is pivotally pinned to a large yoke 202 the forked arms of which embrace a pin secured to the upper end of a bell crank 286 which, like the control arm 16%, is pivoted to the support plate 132 by the pin 162. Thus, when the control lever rotates the shaft 168 clockwise, the lower end of the bell crank is shifted to the left against the tension of a spring 208 secured thereto. A stop pin 210 is provided to limit the extent of this movement.

The lower portion of the bell crank 2436 is pivotally connected at 212 to a slide 214 which moves therewith and is guided along its lower edge by a pin 2% secured to the support plate 132. The right-hand end of this slide is formed into a hook 217 which extends partly around a stud 218 fastened to the upper left-hand corner of the transfer arm 180. Thus, leftward motion of the slide, in response to shifting the control lever 14 to rewind position, rotates the transfer arm 180 about its pivot pin 186 and transfers the driving force of the motor 140 to the supply reel hub shaft 129. In addition, the slide carries at its left-hand end the brake pin 116 which, as described above with reference to Figures 2 and 5, extends into the tape magazine to remove the felt pad 1% from the tape when the machine is conditioned for rewind operation.

The upper edge of the slide 214 is formed, near its right-hand end, with an inclined cam surface 226 engageable with a cam pin 222 secured to the control arm 164' When the slide is shifted to the left (i.e. into its rewind position), the control arm is thereby cammed in a counterclockwise direction around the pivot pin 162 to move the pressure roller 156 out of engagement with the capstan 150. Thus, the magnetic tape will be free to move rapidly back onto the supply reel at high speed.

When it is desired to shift the machine from rewind operation to reproduce condition, the high-speed rotation of the take-up reel 86 during rewind presents a special problem since it is necessary quickly to reverse the direction of rotation of this reel. This problem is solved by means of a unique brake device, generally indicatcd at 224 and associated with the lower end of the transfer arm 1813. This device includes an offset arm 226 pivotally mounted on the pin 186 and carrying on its remote end a nylon finger 223 which is engaged, when the machine is conditioned for recording or reproducing, with the resilient peripheral surface of the disc 184. A spring 230 lightly urges this arm against the disc, but with the disc rotating in a clockwise direction, the finger 228 develops effectively no restraining frictional force.

The brake device 224 also includes a second offset arm 232 secured by an adjustment screw 234 to the first arm 226 and pivotally mounted on the pin .186. This second arm is formed at its remote end with an upstanding hook member 236 which engages the left-hand edge of the transfer arm 130. When the transfer arm is shifted to the left to condition the machine for rewind operation, it carries the offset arms 226 and 252 with it and thereby lifts the nylon finger 228 away from the disc 184. Accordingly, this disc is free to rotate at a relatively high speed (counterclockwise) while the tape is being rewound onto the supply reel.

If, while the machine is rewinding, the control lever 14 is moved to its reproduce position (cg. to listen back to a portion of previously recorded material), the transfer arm 18% shifts to the right and permits the nylon finger 228 to again engage the disc 18% under tento Q) sion of the spring 230. Because the disc is rotatin counterclockwise at this instant, it will tend to rotate offset arm 232 clockwise about the pivot pin 186 and jam the nylon finger hard against the disc surface. This jamming action almost immediately brakes the disc to a stop. Thereafter, the rotary force imparted to the disc by the friction wheel 182 quickly starts the disc rotat-' ing in a clockwise direction to take up the slack of the" tape driven by the capstan 150. Once the disc is rotat ing clockwise, of course, the friction developed by the finger drops essentially to zero since there is then no tendency for this finger to jam against the disc sur face.

Referring now to the upper left-hand corner of Figure 9, means are provided for interlocking the on-oif control lever 12 with the control lever 14 (Figure 8) so that the machine will be turned on whenever the control lever is moved to its rewind position. This intcrlock arrangement includes a bias spring 240 wrapped around the shaft 168 with its lower end in engagement with a post 24-2 secured to the support plate 132, and with its upper end engaged with a bend 244 in the lever arm 12 to urge the arm towards its on position. The on-ofi lever normally is held in its off position against this spring urge by the detent action of the small yoke T70 which is pressed upwardly by the control arm under tension of the spring 174. also is provided with a stop pin 246, secured to the sup port plate 132, which rides in a slotted portion of the. ring base 166 to limit its motion.

When the control lever 14- is moved to its rewind position, the control arm 160 will be rota-ted counterclockwise about its pivot pin 162 (as described above) thereby removing the pressure on the small yoke 17% so that the on-off lever 12 then is free to move to its on position under pressure of the bias spring 240. Thus, this interlock arrangement causes the electrical switch contacts to be actuated to connect the batteries to the drive motor 140 whenever the control lever is shifted to rewind.

Referring now to Figures 2 and 8, when the magazine 3%) has been inserted into the casing 10 the magnetic tape 46 will extend in a generally horizontal direction between the pressure roller 156 and the capstan housing F152, and will pass by the pole-pieces 259 of a combination magnetic recording and reproducing head 2%, of conventional design. During recording or reproducing operations, the tape is held tautly against these polepieces in the region thereof between the magazine guide pins 90 and 92 (see also Figures 4 and 5), by virtue of the tension produced by the pulling force of the capstan 154 and the restraining force of the brake pad 1%.

Secured to the upper edge of the magazine, between the pins 9% and 92 and beneath the tape 46, is a shield strip 261a formed of magnetic material (eig. mu-metal) curved to fit the general contours of the magazine. This strip is directly opposite the pole-pieces 259 of the head 26%) and serves to shield these pole-pieces from interference due to external magnetic fields when the machine is conditioned for reproducing operation. A simi-' lar shield 2611) is secured to the magazine between the pins 94 and 96, to accomplish the same function when the magazine is reversed in the casing.

Adjacent the recording and reproducing head 260 there is provided (Figure 8) an erase head 262 comprising a pair of permanent magnets enclosed in a plastic housing. This erase head is secured to the end of a crank arm 26%, pivotally mounted on the support plate 132 by a pin 266, to permit movement of the erase head towards and away from the tape. The crank arm is urged in a clockwise direction, to press the erase head against the tape, by a wire spring 268 which is wrapped about a stud 270 with its left-hand end bearing against a small pin 272 on the crank arm and its righthand end bear The on-off lever 12 ing against -a small pin 274 secured to the support plate.

When the control lever 14 is in its reproduce or rewind positions, the erase head 262 is held (as shown) away from the magnetic tape by a cam finger 276 on the crank arm which abuts the outer surface of the circular base 278 of the control lever. However, when the control lever is moved to its record position, the cam finger 276 drops into a recess 278a formed in this circular base and the erase head 262 moves down to contact the tape passing by. Thus, during recording, the tape is cleared of magnetic impressions immediately preceding its contact with the recording head 260.

Secured to the control lever shaft 168 is a spring arm 280 which presses downwardly against the control lever 14 so that, to condition the machine for recording, the user must lift the control lever upwards in order to avoid interference with the step 282 (Figure 1) formed in the slot in the casing through which the lever extends.

Although a specific preferred embodiment of the invention has been set forth in detail, it is desired to emphasize that this is not intended to be exhaustive or necessarily limitative; on the contrary, the showing herein is for the purpose of illustrating one form of the invention and thus to enable others skilled in the art to adapt the invention in such ways as meet the requirements of particular applications, it being understood that various modifications may be made without departing from the scope of the invention as limited by the prior art.

We claim:

1. For portable recording equipment of the type adapted to be hand-carried and having a self-contained source of operating power, and wherein means are pro vided for driving linear recording media past a recording head to form impressions on the media in accordance With sound signals developed by a microphone, apparatus comprising, in combination, a casing, a recording magazine removably secured to said casing, one side Wall of said magazine being formed with a pair of apertures, a supply reel and a take-up reel positioned adjacent one another in said magazine having central portions extending outwards through said apertures to serve as loose-fitting hearings to hold said reels approximately in place when the magazine is removed from the casing, each of said central portions being formed with a recess coaxially aligned with the corresponding reel, and a drive mechanism secured to said casing and arranged to move a strip of linear recording media from said supply reel to said take-up reel, said drive mechanism including a pair of hubs each drivably engaged with a respective one of said recesses to hold the reels securely in place and to transmit rotary motion thereto, at least one of said hubs having a tapered end to assure easy and rapid engagement with the corresponding recess when the magazine is secured in operative position to said casing.

2. For portable recording equipment of the type adapted to be hand-carried and having a self-contained source of operating power, and wherein means are provided for driving a linear recording media past a recording head to form impressions on the media in accordance with sound signals developed by a microphone, apparatus comprising, in combination, a casing, a magazine removably secured to said casing, said magazine including two parallel side Walls each formed with a pair of circular apertures to form two sets of oppositelylocated apertures, a supply reel and a take-up reel positioned adjacent one another in said magazine, central portions on each of said reels including ring-shaped elements having an outer diameter substantially less than the diameter of said apertures and extending axially outwards through said sets of apertures to hold said reels loosely in place when the magazine is removed from the casing, each of said central portions being formed on opposing sides thereof with a pair of recesses coaxial with the corresponding reel, and a drive mechanism secured to said casing and arranged to move a strip of linear recording media from said supply reel tosaid take-up reel, said drive mechanism including a pair of hubs extending through a corresponding one of said pairs of apertures and each drivably engaged with a respective one of said recesses to hold the reels firmly in place with respect to lateral movement and to transmit rotary motion thereto, said hubs having tapered ends to assure easy and rapid engagement with the corresponding recesses when the magazine is secured in operative position to said casing.

3. For portable recording equipment of the type adapted to be hand-carried and having a self-contained source of operating power, and wherein means are provided for driving a magnetizable tape at substantially constant lineal speed past a magnetic recording head to form impressions on the tape in accordance with sound signals developed by a microphone, apparatus comprising, in combination, a casing having an opening in one side thereof, a tape magazine positioned in said casing and removable therefrom through said opening, one side Wall of said magazine being formed with a pair of apertures, a supply reel and a take-up reel positioned adjacent one another in said magazine having central portions extending axially outwards through said apertures to hold said reels loosely in place when the magazine is removed from the casing, each of said central portions being formed with a cylindrical recess coaxial with the corresponding reel, the interior sides of said recesses being formed with spline-like teeth extending parallel to the corresponding reel axis, and a drive mechanism secured to said casing and arranged to move tape from said supply reel to said take-up reel, said drive mechanism including a pair of circular hubs each engaged with one of said recesses. to hold the reels in place and to transmit rotary motion thereto, the sides of said hubs being formed with spline-like teeth to provide a driving engagement with the corresponding teeth of said recesses, said hubs also being formed with tapered ends to assure easy and rapid engagement with the corresponding recess when the magazine is inserted into operative position within said casing.

4. For portable recording equipment of the type adapted to be hand-carried and having a self-contained source of operating power, and wherein means are provided for driving a magnetizable tape at substantially constant lineal speed past a magnetic recording head to form impressions on the tape in accordance with sound signals developed by a microphone, apparatus comprising, in combination, a casing having an opening in one side thereof, a cover extending over said opening and releasable from said casing, a tape magazine positioned in said casing and removable through said opening, said magazine including a pair of opposed side-Walls each formed with a pair of apertures, a supply reel and a take-up reel positioned adjacent one another in said magazine having central portions extending axially outwards through said apertures to hold said reels loosely in place when the magazine is removed from the casing, each of said central portions being formed with a recess aligned with the corresponding reel axis, each of said central portions including on the side thereof opposite to said recess an upstanding pin member coaxial with the reel, a drive mechanism secured to said casing and arranged to move tape from said supply reel to said take-up reel, said drive mechanism including a pair of hubs each drivably engaged with one of said recesses to hold the reels firmly in place with respect to lateral movement thereof and to transmit rotary motion thereto, at least one of said hubs having a tapered end to assure easy and rapid engagement with the corresponding recess when the magazine is inserted into operative position within said casing, and a pair of resilient members secured to said cover and pressed respectively against the exposed ends of said pins to serve as thrust bearings for rotation of said reels.

5. For portable recording equipment of the type adapted to be hand-carried and having a self-contained source of operating power, and wherein means are provided for driving a magnetizable tape at substantially constant lineal speed past a magnetic recording head to form impressions on the tape in accordance with sound signals developed by a microphone, apparatus comprising, in combination, a casing having an opening in one side thereof, a releasable cover extending over said opening, a generally rectangular-shaped magazine positioned in said casing and removable therefrom through said opening, said magazine including a pair of opposed parallel side walls each formed with a pair of apertures, one of said side walls lying adjacent said cover, a supply reel and a take-up reel positioned sideby-side in said magazine, central portions on each of said reels having ring elements extending axially outwards through the apertures in both of said side walls to hold said reels in place when the magazine is removed from the casing, said apertures being substantially larger than the outer diameters of said ring elements, each of said central portions having a transverse wall extending across the interior of the corresponding ring element to form a pair of opposed cylindrical recesses coaxial with the corresponding reel and opening out towards opposite sides thereof, the inner side surface of each recess being formed with splinelike teeth, each of said transverse walls having secured thereto a pair of upstanding pin members located in said opposed recesses and coaxial with the corresponding reel, a drive mechanism secured to said casing and arranged to move tape from said supply reel to said take-up feel, said drive mechanism including a pair of hubs extending through a corresponding one of said pairs of apertures and each engaged with one of said recesses to hold the reels in place with respect to lateral movement thereof and to transmit rotary motion thereto, the sides of said hubs being formed with spline-like teeth to mesh with the internal teeth of the engaged recesses, said hubs having tapered ends to assure easy and rapid engagement with the corresponding recess when the magazine is inserted into operative position through said opening, a pair of spring arms secured to said cover, and a pair of bearing pads mounted respectively on said arms and each pressed against the free end of a corresponding one of said pins to form a thrust bearing for transmission of rotary driving power to said reels.

6. For portable recording equipment of the type adapted to be hand-carried and having a self-contained source of operating power, and wherein means are provided for driving a linear recording media past a recording head to form impressions on the media in accordance with sound signals developed by a microphone, apparatus comprising, in combination, a casing having means to receive a magazine having a supply reel and a take-up reel rotatably mounted adjacent one another, a drive mechanism secured to said casing and arranged to move a strip from said supply reel to said take-up reel, said drive mechanism including a pair of rotatable members each drivably engageable with a corresponding one of said reels, a media-movement control element operatively connected to said drive mechanism and arranged to condition the recording equipment for recording or rewinding operation, a one-directional brake device engaged with one of said rotatable members to apply a restraining force thereto only when said one member is rotating in a reverse direction, and coupling means connecting said control element to said brake device and arranged to move said device out of engagement with said one member when said equipment is conditioned to drive said one member in reverse direction.

7. For portable recording equipment of the type adapted to be hand-carried and having a self-contained source of operating power, and wherein means are provided for driving linear recording media past a recording head to form impressions on the media in accordance with sound signals developed by a microphone, apparatus comprising, in combination, a casing having means on one side thereof to receive a magazine having a supply reel and a take-up reel rotatably mounted adjacent one another, a drive mechanism secured to said casing and arranged to move a strip from said supply reel to said take-up reel, said drive mechanism including first and second rotatable members each drivably engageable respectively with said supply and take-up reels, a media movement control element operatively connected to said drive mechanism and arranged to condition the recording equip ment for recording or rewinding operation, a one-directional brake device engageable with said second rotatable member to apply an effective restraining force thereto only when said second member is rotating in rewind direction, linkage means for coupling said brake device to said control element and arranged to move said device out of engagement with said second rotatable member when said equipment is conditioned by said control element for rewind operation, whereby when said equipment subsequently is shifted to recording operation said brake device engages said second member and rapidly stops its rotation so that said second member may thereafter be rotatably driven in recording direction without any effective braking force thereon.

8. For portable recording equipment of the type adapted to be hand-carried and having a self-contained source of operating power, and wherein means are provided for driving a magnetizable tape at substantially constant lineal speed past a magnetic recording head to form impressions on the tape in accordance with sound signals developed by a microphone, apparatus comprising, in combination, a casing having an opening in one side thereof for insertion of a tape magazine having a supply reel and a take-up reel rotatably mounted adjacent one another, a drive mechanism secured to said casing and arranged to move tape from said supply reel to said take-up reel, said drive mechanism including first and second rotatable members each drivably engageable respectively with said supply and take-up reels, a friction wheel member selectively engageable with either of said rotatable members, a movably mounted transfer arm for carrying said friction wheel member, a tape-movement control element operatively connected to said transfer arm and arranged to condition the recording equipment for recording or rewinding operation by selectively engaging said friction wheel member with either one of said rotatable members, a one-directional brake device having an element urged into contact with said second rotatable member and arranged to apply a restraining force thereto only when said second member is rotating in a direction to feed tape back onto said supply reel, and linkage means connecting said brake device to said transfer arm and arranged to move said device out of engagement with said second member when said equipment is conditioned by said control element for rewinding operation.

9. For portable recording equipment of the type adapted to be hand-carried and having a self-contained source of operating power, and wherein means are provided for driving a magnetizable tape at substantially constant lineal speed past a magnetic recording head to form impressions on the tape in accordance with sound signals developed by a microphone, apparatus comprising, in combination, a casing having an opening in one side thereof for insertion of a tape magazine having a supply reel and a take-up reel rotatably mounted adjacent one another, a drive mechanism secured to said casing and arranged to move said tape from said supply reel to said take-up reel, said drive mechanism including first and second rotatable members each drivably engageable respectively with said supply and take-up reels, a tapemovement control element operatively connected to said drive mechanism and arranged to condition the recording equipment for recording or rewinding operation, a onedirectional brake device engageable with said second rotatable member and arranged to apply an effective restraining force thereto only when said one member is rotating in a direction to feed tape back onto said supply reel, said brake device including a pivotally-mounted arm carrying a pad in contact with a peripheral surface of said second member, said arm being mounted for movement in a plane transverse to the axis of said second member and positioned so that a line between its pivot point and the point of contact with said peripheral surface makes an angle substantially diiferent from ninety degrees and greater than zero degrees with a line tangent to said peripheral surface at said point of contact, and means coupling said arm to said control element and arranged to move said pad out of engagement with said second member when said equipment is conditioned for rewind operation.

10. For use with sound recording or reproducing equipment of the type having means for driving linear record media past a transducing head; apparatus comprising, in combination: a casing, a record media magazine removably secured to said casing, one side wall of said magazine being formed with a pair of apertures, a supply reel and a take-up reel positioned side-by-side in said magazine with their axes adjacent said apertures respectively, at least one of said reels having a central portion extending outwards through the corresponding one of said apertures, said corresponding one aperture being larger than said central portion so that said magazine side wall serves as a loose-fitting bearing to hold said one reel approximately in place when the magazine is removed from the casing, said central portion being formed with motion receiving means; bearing means rotatably mounting said other reel in said magazine; and a drive mechanism secured to said casing and arranged to move a strip of linear record media from said supply reel to said takeup reel; said drive mechanism including motion transmitting means drivably engaged with said motion receiving means of said one reel to transmit rotary motion to said one reel while said magazine is operatively secured to said casing, said motion transmitting means and said motion receiving means both having interengageable opposed surfaces, at least one of said surfaces being tapered to produce a lateral force on said central portion of said one reel while said magazine is being secured in place, so as automatically to align said one reel in position to assure easy and rapid engagement between said motion transmitting means and said motion receiving means; said drive mechanism further including a rotatable member engaged with said other reel to transmit rotary motion thereto.

11. For use with sound recording or reproducing equipment of the type having means for driving linear record media past a transducing head; apparatus comprising, in combination: a casing, a record media magazine removably secured to said casing, one side wall of said magazine being formed with a pair of apertures, a supply reel and a take-up reel positioned side-by-side in said magazine with their axes adjacent said apertures respectively, said reels having respective central portions extending outwards through the corresponding apertures, said apertures being larger than said central portions so that said magazine side wall serves as a loose-fitting bearing to hold said reels approximately in place when the magazine is removed from the casing, said central portions being formed with motion receiving means; and a drive mechanism secured to said casing and arranged to move a strip of linear record media from said supply reel to said takeup reel; said drive mechanism including first and second motion transmitting means drivably engaged with the motion receiving means of said reels respectively to transmit rotary motion to said reels while said magazine is operatively secured to said casing; each of said motion transmitting means and said motion receiving means having interengageable opposed surfaces at least one of which is tapered to produce lateral forces on said central portions of said reels while said magazine is being secured in place, so as automatically to align said reels in position to assure easy and rapid engagement between said motion transmitting means and said motion receiving means respectively.

12. Apparatus as claimed in claim 11, wherein said motion transmitting means comprise hubs rotatably mounted on said casing, said motion receiving means comprising recesses into which said hubs fit when said magazine is secured to said casing; the interior sides of each of said recesses being provided with a first set of spline- ]ike teeth, each of said hubs being provided with a second set of spline-like teeth to engage said first set of teeth and provide positive driving action between said hubs and said reels.

13. Apparatus as claimed in claim 12, wherein the teeth of at least one of said sets of teeth are tapered radially so as to present relatively narrow edges at the tips thereof, whereby to accommodate quick engagement with the other of said sets of teeth.

14. Apparatus as claimed in claim 12, wherein the ends of said hubs are tapered to produce said lateral force for aligning said reels in position; the ends of said first set of teeth, adjacent the openings of said recesses, being cut back at an angle to form tapered surfaces engageable with the ends of said hubs.

References Cited in the file of this patent UNITED STATES PATENTS 2,292,929 Crebbs Aug. 11, 1942 2,574,218 Lynch Nov. 6, 1951 2,609,457 Thurm Sept. 2, 1952 2,612,565 Heller Sept. 30, 1952 2,652,910 Godeck Sept. 22, 1953 2,659,653 Owens Nov. 17, 1953 2,664,251 Berlant Dec. 29, 1953 2,681,950 Owens June 22, 1954 2,686,637 Dashiell et a1 Aug. 17, 1954 2,741,439 Dale et a1 Apr. 10, 1956 

